# Modal vs OpenAI API: who uses which

On usedby, 28 companies use Modal and 37 use OpenAI API. 1 company uses both, including Doppel. Counts include every proof level, job-post signals included; each company keeps its proof level on each side. Latest check 2026-10-18: 64 of 65 public lines checked.

## Side by side

|  | [Modal](https://www.usedby.ai/tools/modal.md) | [OpenAI API](https://www.usedby.ai/tools/openai-api.md) |
|---|---|---|
| Public customers | 28 | 37 |
| Confirmed | 0 | 3 |
| Observed | 28 | 33 |
| Signals (job posts) | 0 | 1 |
| Top industries of customers (every proof level) | Artificial Intelligence (15), DevTools & Infrastructure (3), Media & Publishing (3) | DevTools & Infrastructure (6), Artificial Intelligence (4), Marketplace (4) |
| Category | AI inference & GPU cloud | Foundation models & model APIs |
| Data processing terms | A data processing agreement is available. ([modal.com](https://modal.com/legal/dpa), checked 2026-10-07) | — |

## Companies that use both

Every proof level counts; the proof level of each side is shown, strongest proofs first. The first public proof is not an adoption date.

| Company | Proof, Modal | Proof, OpenAI API | First public proof, Modal | First public proof, OpenAI API |
|---|---|---|---|---|
| [Doppel](https://www.usedby.ai/companies/doppel.md) | Observed | Observed | On or before October 2026 | On or before October 2026 |

---
Source: https://www.usedby.ai/compare/modal-vs-openai-api · How we check: https://www.usedby.ai/methodology